While the documents do not specifically name AT&T, they use code names that the Times and several ex-intelligence officials said point to the telecommunications company.

The article says the documents are dated from 2003 through 2013 and show how AT&T used legal rules and secret court orders to give the NSA access to billions of emails sent through its U.S. network. They include Internet traffic at U.N. headquarters in New York.

It also handed over more than 1 billion telephone call records to the NSA.

According to the documents, the NSA regarded AT&T as a partner in the domestic surveillance business, not a contractor.

AT&T spokesman Brad Burns told VOA that the company does not "provide information to any investigating authorities without a court order or other mandatory process, other than if a person's life is in danger and time is of the essence. For example, in a kidnapping situation, we could provide help tracking down called numbers to assist law enforcement."

Documents leaked by Snowden showing that the NSA had spied on the telephone calls and emails of U.S. citizens and foreigners with no court order outraged millions who saw the actions as violations of their right to privacy.

The NSA says the activities helped foil several terrorist plots and were a key in keeping the country safe.

The administration of former President George W. Bush authorized the spying under the Patriot Act, which Congress passed not long after the September 11, 2001, terrorist attacks on New York and Washington.

President Barack Obama signed a bill earlier this year reforming the way the NSA collects electronic communications.